XXXIV

Annabeth descends a rope ladder into Rome’s shallow water tunnel, wary that the route may intersect a remnant of Daedalus’s Labyrinth. Following the flickering Mark of Athena and laying a guide string, she discovers a bricked breach leading to a long, bench-lined chamber with mosaics and a carved altar.

Inside, she notices stress fractures in the ceiling and a timeline floor mosaic marked with ranks. Human remains and a corroded dagger reveal past demigod failures. Purple Roman Lares materialize, led by a pater in ritual garb, condemning a Greek and especially a girl for intruding on Mithras’s mysteries.

Cornered with her exit sealed, Annabeth analyzes the symbols and bluffs authority as a “magna mater.” She identifies the seven Mithraic ranks and the ordeals of fire and dagger, unnerving the ghosts. The pater insists she choose an ordeal, while hinting the “weaver” enlisted them to destroy Athena’s children.

Drawing deductions from the altar’s imagery, Annabeth claims a third test: Mithras’s birth from stone. She then asserts mastery over the chamber’s stones and threatens to fell the cavern with one strike. Reading the architecture’s failing capstone, she times her blow.

Annabeth shatters the capstone with her dagger. The far end collapses, burying the altar and pater as fissures race across the ceiling. Using the chaos, she smashes through the bricked doorway and dives into darkness, escaping as the cavern of Mithras implodes behind her.